(1) Field of the invention
The present invention relates to carbazole compounds having antipsychotic action.
(2) Prior Art
Antipsychotic drugs are used not only for the treatment of schizophrenia but also for the treatment of the problem behaviors (e.g. aggressive behavior, excitation, poriomania and delirium) accompanied by cerebrovascular diseases and senile dementia. However, there is a serious problem that prior antipsychotic drugs induce strong extrapyramidal tract injury as a side effect. In order to solve such a problem, recent antipsychotic drugs are being developed by approaching to the reaction mechanism which is different from that of the prior drugs. Among these drugs are sigma receptor antagonists. The sigma receptor is considered to participate alienation such as hallucina. The compounds which have a specific affinity for the receptor have antipsychotic action without showing extraphramidal tract injury. As an example of such compounds is known rimcazole, but, of which affinity and specificity for sigma receptor are not sufficient.
As a result of earnest researches to compounds having a carbazole skeleton, the present inventors have found novel carbazole compounds having specific and strong affinity for sigma receptor without extrapyramidal tract injury, and have accomplished the present invention.